141 research outputs found
Suppression of experimental arthritis through AMP-activated protein kinase activation and autophagy modulation
Autophagy plays a central role in various disease processes. However, its contribution to inflammatory arthritides such as rheumatoid arthritis (RA) is unclear. We observed that autophagy is engaged in the K/BxN serum transfer model of RA but autophagic flux is severely impaired. Metformin is an anti-diabetic drug that has been shown to stimulate autophagy. Induction of autophagic flux, through metformin-mediated AMP-activated protein kinase (AMPK) activation and interruption of mammalian target of rapamycin (mTOR) signaling mitigated the inflammation in experimental arthritis. Further investigation into the effects of metformin suggest that the drug directly activates AMPK and dose-dependently suppressed the release of TNF-α, IL-6, and MCP-1 by macrophages while enhancing the release of IL-10 in vitro. In vivo, metformin treatment significantly suppressed clinical arthritis and inflammatory cytokine production. Mechanistic studies suggest that metformin exerts its anti-inflammatory effects by correcting the impaired autophagic flux observed in the K/BxN arthritis model and suppressing NF-κB-mediated signaling through selective degradation of IκB kinase (IKK). These findings establish a central role for autophagy in inflammatory arthritis and argue that autophagy modulators such as metformin may represent potential therapeutic agents for the treatment of RA
Signal for CP violation in decays
We analyze the partial rate asymmetry in
decays () which results from the interference of
the nonresonant decay amplitude and the resonant amplitude for followed by the decay . The CP
violating phase can be extracted from the measured asymmetry. We find
that the partial rate asymmetry for is
, while for it amounts .Comment: 3 pages, latex, no figures, Talk given by S. Fajfer at the Hyperons,
Charm and Beauty Hadrons, Genova, Italy, 30 June -3 July 1998, to appear as
proceedings in Nucl. Phys.
B -> K1 gamma and tests of factorization for two-body non leptonic Bdecays with axial-vector mesons
The large branching ratio for B-> K1 gamma recently measured at Belle implies
a large B -> K1 transition form factor and large branching ratios for non
leptonic B decays involving an axial-vector meson. In this paper we present an
analysis of two-body B decays with an axial-vector meson in the final state
using naive factorization and the B -> K1 form factors obtained from the
measured radiative decays. We find that the predicted B -> J/psi K1 branching
ratio is in agreement with experiment. We also suggest that the decay rates of
B -> K1 pi, B -> a1 K and B -> b1 K could be used to test the factorization
ansatz.Comment: 8 pages; 7 new references included and a comment on K2(1430) in the
final state adde
FACTORS AFFECTING ECOTOURISM LOYALTY WITH THE MODERATING ROLE OF SOCIAL INFLUENCE - EMPIRICAL EVIDENCE IN VIETNAM
Today, ecotourism has become more common and attractive for tourists who love to explore nature and experience the
cultural heritage. In the 4.0 age of technology, social networking not only helps visitors find suitable destinations to visit easily
but also provides visitors with a place to leave comments or reviews after the trips. This study aims to qualify the relationships
between electronic-worth-of-mouth (eWOM), social influence (SI), destination image (DI), tourist satisfaction (SAT), and
ecotourism loyalty (EL). The study applied the PLS-SEM model to estimate 499 observations at ecotourism sites in Vietnam as
empirical evidence. The research results show that all the factors in the research model have positive and significant effects on
EL. In particular, DI and SAT, directly and indirectly, affect EL; while eWOM and SI only have direct effects on EL.
Additionally, it was found that the effect of eWOM on EL increased with the moderating role of SI
B => \pi \pi \ell \nu decays in a QCD relativistic potential model
In the framework of a QCD relativistic potential model we evaluate the form
factors describing the exclusive decay B => \pi\pi \ell \nu. The calculation is
performed in a phase space region far away from the resonances and therefore is
complementary to other decay mechanisms where the pions are produced by
intermediate particles, e.g. in the chiral approach. We give an estimate of the
contribution of the non resonant channel of the order of BR(B- => \pi+ \pi-
\ell \nu) \approx 2.2 x 10^(-4).Comment: 14 pages LaTeX2e + 3 figures, Napoli Preprint DSF 99/3
Final State Interactions in and Decays
We analyze final state strong interaction effects in and decays using the Regge model. We find that, due to the smallness of
the contributions from the non-leading Regge trajectories (, ,
etc.), final state interaction phases are small if the Pomeron coupling to the
charm quark is suppressed in comparison to lighter quarks. Our conclusion is
that for decays into states containing charm, final state interaction
effects should play a minor role.Comment: 10 pages, LaTeX, accepted for Physics Letters
Pantoea stewartii subsp. stewartii, the causative agent of Thai jackfruit’s bronzing disease and its possible host range in Vietnam
The bronzing disease of Thai jackfruit (Artocarpus heterophyllus Lam.) has recently appeared in Vietnam, causing a significant loss for farmers, but its control method is still restricted. In this study, we identified pathogens based on morphological and molecular characterizations. A total of 25 bacterial isolates were isolated from diseased samples. The bacterium produces white or yellow pigment in culture, is gram-negative, slightly pleomorphic, non-motile, facultatively anaerobic, short-rod, and catalase-positive. It hydrolyzes gelatin and starch but not tween 80, and produces acid from glucose, sucrose, and lactose. The bacterium does not produce indole and does not produce hypersensitivity to tobacco. The results of sequencing of the encoded region of synthesis of capsular polysaccharide (cpsD) and pathogenicity-related genes HrpS confirmed that the causative agent is Pantoea stewartii subsp. stewartii. The pathogen’s possible host range could be traditional jackfruit varieties, fruits, and crops such as durian, longan, mango, tomatoes, broccoli, pumpkin, cucumber, corn, rice, sweet potatoes, water spinach, peanuts, and green beans. The P. stewartii subsp. stewartii could enter the host plant cell through open wounds or natural openings such as stomata. The results confirmed the presence of P. stewartii subsp. stewartii in Vietnam and suggest that the jackfruit tree should not be planted in plantations with these crops to prevent cross-contamination and the spread of pathogens
Neutrinos in 5D SO(10) Unification
We study neutrino physics in a 5D supersymmetric SO(10) GUT. We analyze
several different choices for realizing the See-Saw mechanism. We find that the
"natural" scale for the Majorana mass of right-handed neutrinos depends
critically on whether the right-handed neutrinos are located in the bulk or
localized on a brane. In the former case, the effective Majorana mass is
"naturally" of order the compactification scale, about 10^{14} GeV. Note, this
is the value necessary for obtaining a light tau neutrino mass approximately
10^{-2} eV which, within the context of hierarchical neutrino masses, is the
right order of magnitude to explain atmospheric neutrino oscillations. On the
other-hand when the right-handed neutrino is localized on the brane, the
effective Majorana mass is typically larger than the compactification scale.
Nevertheless with small parameters of order 1/10 - 1/30, an effective Majorana
mass of order 10^{14} GeV can be accommodated. We also discuss the constraints
on model building resulting from the different scenarios for locating the
right-handed neutrinos.Comment: 24 page
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